The present invention relates to apparatus for subdividing a web of flexible material into discrete sections, e.g., into blanks which can be used in packing machines for cigarettes or other smokers' products. More particularly, the invention relates to an intermittently operated severing or subdividing apparatus which moves the web in stepwise fashion and is preferably designed to subdivide a web having marginal notches along which the blanks can be folded preparatory to conversion into imprinted or unprinted wrappers, portions of wrappers, envelopes or the like.
It is already known to provide a severing or subdividing apparatus for webs of flexible material (such as paper, cardboard, metallic foil, sheets made of synthetic plastic material or the like) with means for intermittently advancing the web lengthwise so as to place successive selected portions of the web into register with cutting or severing instrumentalities. In many instances, the advancing means includes a first unit which effects a coarse transport of the web through a distance which approximates and somewhat exceeds the length of a section or blank, and a second unit which thereupon moves the web rearwardly so as to eliminate the discrepancy between the extent of coarse transport and the desired length of a blank. Reference may be had to German Auslegeschrift No. 1,019,545. The rearward movement of the web is terminated when suitable detent means penetrate into marginal notches of the web.
A drawback of conventional apparatus of the above outlined character is that the intervals between successive severing steps are rather long. This is due to the fact that the direction of movement of the web must be reversed upon completion of coarse advancement in order to move the aforediscussed marginal notches into register with the detent means.